Along the lines of other commenters, if your goal is to enlighten non-agile developers about the beauty of a flexible language and run-time environment like perl, eval EXPR is not the thing to do it with (IMHO).
in reply to Small examples of string eval
eval EXPR is what I use in php or Sybase stored procedures, to make up for the lack of expressiveness in the language.
While eval EPXR has definite uses (such as the quoted example of dynamically loading packages), probably 90% of the times that eval EXPR is used in Perl code, faster and more safe code could be written to do the same thing using techniques such as those shown in other responses (such as closures/currying etc.).
In fact, if these developers are serious C or Java developers and talk about things like compiler optimisations then they are going to recognise most eval EXPR based Perl code as a weak solution to hard problems. It would be sad for that to be their first Perl experience as Perl offers such better solutions to those problems than does, say, C or Java.